1. Field of the invention
The present invention relates to a semiconductor device and an information management system for this semiconductor device, and in particular, it relates to a semiconductor device and an information management system therefor that achieve implementation of efficient and accurate information management in regard to the production processes for manufacturing the semiconductor device by utilizing a two-dimensional bar code pattern.
2. Description of the Related Art
A manufacturing method for manufacturing semiconductor devices normally consists of an extremely large number of processes. In a typical manufacturing method for producing semiconductor devices, first, during the wafer processing process, a photolithography step, an etching step, a washing step and the like are performed repeatedly on the surface of the wafer to form the required semiconductor chips. Next, testing for a pass/fail assessment of the individual chips formed on the wafer is performed using a probe apparatus to obtain mapping data, and then it is sent to the wafer assembly process. During the wafer assembly process, first, the wafer is divided into individual dies in a dicing step. Next, good dies are picked up in conformance to the mapping data and are mounted at a lead frame in a bonding step. Then, in a wire bonding step, the connection electrodes and the lead-out terminals for the semiconductor chips are connected through wire bonding. After that, in the packaging process, mold forming is performed on the semiconductor chips using a thermosetting resin and specific information is marked on the surface of the package to complete the semiconductor device.
As explained above, an extremely large number of complicated processes must be implemented to complete the semiconductor device, and it is necessary to implement accurate information management in regard to the information on the semiconductor product in the individual processes. In semiconductor manufacturing methods in the prior art, the management of information on the semiconductor devices as they are distributed throughout the processes is relatively easy since the main focus of the manufacturing methods in the prior art is to mass produce semiconductor devices with the same specifications to take advantage of large scale production. In other words, since, in the semiconductor manufacturing methods in the prior art, semiconductor devices processed through the same manufacturing system are distributed through the processes as one lot unit, each lot is normally processed under the same conditions, making information management relatively easy.
However, in recent years, as semiconductor devices have come to be used widely in general consumer products and industrial parts, great market demand for many different types of semiconductor devices produced in small quantities, such as ASIC (application specific integrated circuits) and SOS (system on silicon) has arisen. Quantity-wise, one wafer may sometimes assure a sufficient quantity to produce a plurality of types of such semiconductor devices for specific applications.
At the same time, there are situations in which products can be shipped as long as a portion of the chips are good, as in the case of large capacity memory chips. Thus, it is necessary to implement information management separately for the individual chips within a given wafer.
For this purpose, in semiconductor manufacturing methods in the prior art, the physical distribution of semiconductor devices throughout various processes is managed by marking ID information, such as numerals and alphabetical characters, on the surface of semiconductor chips on the wafer or on a semiconductor package that is sealed with resin. However, there is a limit to the quantity of information that can be recorded using alphanumeric characters. Furthermore, it is necessary to perform edge recognition processing when reading alphanumeric characters, which is difficult. There is an added problem with this method, in that it is vulnerable to dirt and scarring.
Alternatively, since a read operation can be performed with ease by employing an optical apparatus, various types of information are recorded by utilizing one-dimensional barcode patterns in the inter-process physical distribution of semiconductor devices in some semiconductor manufacturing methods. However, there is a limit to the quantity of information that can be recorded in a one-dimensional barcode pattern per unit area, and since the area occupied by the one-dimensional barcode pattern must increase for a larger quantity of information to be carried, information management using one-dimensional barcode patterns will not always be sufficient in a semiconductor manufacturing method in which semiconductor devices with only limited space available for recording information are handled.
Furthermore, in the prior art, since it is sometimes difficult to make the various types of ID information provided at a semiconductor package correspond to information related to individual chips sealed in the semiconductor package, there is a concern that information management in a semiconductor manufacturing method for producing many different types of products in small quantities cannot be implemented fully.